The invention relates to a powder mixture, containing formaldehyde- and/or formic acid-releasing compounds which have skin-tanning properties, which powder mixture contains an agent which forms sulphite ions.
It has been known for some time that compounds which have a ketol group ##STR1## preferably hydroxymethyl ketones, in particular dihydroxyacetone, have a self-tanning effect on human skin. This self-tanning effect is essentially based on a Maillard reaction between the ketol group of these compounds and the amino acids of the skin.
The hue obtained in this reaction can be further enhanced by adding certain adjuvants (for example EP 0 425 324).
Moreover, WO 91/12222 proposes to stabilize dihydroxyacetone (DHA) by coating at least part of it, in its dimeric form, with a water-impermeable composition. This publication furthermore proposes to employ formal-dehyde-releasing compounds to prevent the bacterial degradation of DHA.